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From WCAG WG
WCAG definition of label
text or other component with a text alternative that is presented to a user to identify a component within Web content
Note 1: A label is presented to all users whereas the name may be hidden and only exposed by assistive technology. In many (but not all) cases the name and the label are the same.
Note 2: The term label is not limited to the label element in HTML.
Additional guidance when applying to Electronic Documents and Software Aspects of Products
This applies directly as written, and as described in WCAG 2.0 glossary replacing "Web Content" with "Content".